The famous Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) appears in the northern constellation of Lyra. It is a prominent example of a planetary nebula. This is a shell of ionized gas expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.
Read more about Ring Nebula: History, Observation, Properties
Famous quotes containing the word ring:
“Tell me where is fancy bred,
Or in the heart or in the head?
How begot, how nourished?
Reply, reply.
It is engendered in the eyes,
With gazing fed, and fancy dies
In the cradle where it lies.
Let us all ring fancy’s knell.
I’ll begin it. Ding, dong, bell.”
—William Shakespeare (1564–1616)